In medical procedures involving internal access to blood vessels, it is necessary once the procedure is concluded to prevent substantial bleeding through the opening created and/or maintained by a device (e.g. sheath or introducer) to access the blood vessel interior. External pressure applied via the skin to the vessel has been a primary way to close or minimize the hole so that natural clotting and repair can occur. However, applying such pressure following removal of the access device can result in significant blood loss, is difficult for a physician, nurse or other professional to apply, and can result in minimizing or stopping flow in the vessel, which over time can have negative consequences.
Closures for holes in vascular walls have been proposed that include plugs, seals or other blocking pieces placed in or over the hole. A number of structures and techniques have been proposed for placing and holding such closures, so that minimal amounts of blood escape the vessel. It has been found, however, that such closures can be less efficacious in sealing vascular or other tissue holes that are relatively large. While such closures may work well in closing holes made by small introducers, as for example those used to introduce small catheters for infusion of contrast agents or medicaments, they may not be able to be easily or efficiently placed to close larger openings, as for example those made by introducers for intra-aortic balloon (IAB) pump or abdominal aortic aneurysm (AAA) repair. Existing closures may be poorly centered over a hole, allowing a portion of the hole to be uncovered, or a portion of the closure may bend due to blood flow, creating a gap between the closure and the vessel tissue. In such cases, leakage of blood and resultant complications can occur.
Likewise, other types of relatively large tissue openings (e.g. patent foramen ovale (PFO), fistulae, or the like) present difficulties for closure by existing devices. Accordingly, there is a need for improvement in this area.